The Revolutionary War has ended, and the first Constitutional Convention writes the Declaration of Independence and they are now officially free from Britain's rule.
The Great Compromise
The Articles of Confederation are written and published, and are the first official government in the U.S. Unfortunately, there are many issues with it.
The 3/5 Compromise
In May 1787, the Constitutional Convention meets again with Representatives from each state. They are discussing the issues with the Articles of Confederation, and what to do about them. Eventually, they decide to write something new.
The Final Constitution
The Great Compromise was between the Virginia and New Jersey plans. It decided that there would be a two-house legislative branch, and that each state had a certain amount of representatives based on the population. All states have an equal say in Senate.
Due to the fact that lots of Southern states had slaves, but Northern didn't, they were trying to decide if the slaves counted towards the population. Eventually they decided that slaves would count as 3/5 of a person.
Finally after months of revision, the Constitution is written and officially takes the place of the Articles of Confederation. This is a much better version, and improves the government immsenly, and works to this day.